Videos are a good way to inform, instruct, entertain, and so forth. Digital video further increases the appeal of video by simplifying the storage, distribution, and displaying of video. The popularity of digital video can readily be seen in the wide range of digital devices that are capable of displaying video. These digital devices include televisions, personal video devices, smart telephones, enhanced appliances, computers, and so on.
However, the wide range of devices on which to display the digital video has led to a wide range of frame (or image) sizes, with exemplary frame sizes ranging from full high definition and beyond with thousands of pixels per dimension (e.g., 1920×1080) down to handheld telephones with a few hundred pixels or less per dimension (e.g., 320×240) and many in between.
It is usually not practical and/or feasible to make a video at all of the possible or at least the generally accepted frame sizes. Generally, a video is made at one or two frame sizes and then resized or otherwise converted to match the frame size of the display device used to display the video. Popular resizing techniques use scaling, stretching, cropping, and so forth, to force the video into the desired size.
Video retargeting (or simply, retargeting) seeks to change the frame size of a video while preserving important visual features. In retargeting, frames in an existing video are transformed to fit an arbitrary display. Retargeting aims to preserve a viewer's experience by maintaining the information content of important regions of the frames in the video, while fulfilling the display's aspect ratio. Careless retargeting may result in a retargeted video that results in a very poor viewer experience.
Retargeting may be computationally intensive and may require a large amount of memory. Therefore, there is a need for a system and method for retargeting videos that provides good or better viewer experience that does not require a great deal of computational resources, thereby potentially being a real-time process.